(FR #1097) Fix recurring text in Thank-you

Also fixes text rendering, which was broken in several ways.

This patch abandons the templates/txt/**, in favor of on-the-fly
html2txt conversion.  Now it is possible to include a link from
within the unsubscribe function, and the recurring transclusion.

The \t at the beginning of paragraphs is eliminated.

Twig cache files are stored under the Drupal sites/default/files dir.

Change-Id: I6a2b1b40d00ee6924da07f391d7972cc9f6f8783
fix html include path. drop txt templates.

Change-Id: I3cca4fff25dcb6369961507e2645bc28a9a27c58
Merge "(FR #1097) Fix recurring text in Thank-you"
Merge "fix html include path. drop txt templates."
Bugfix for damaged queue failmails

When the rejected message is lacking a correlation ID, produce one.

Change-Id: If2db16dc12475dbcdb5958903148733221af7af9
update civicrm submodule for SA

Change-Id: I723f647664705af80931d75adb1d1d97b99db69c
Merge remote-tracking branch 'origin/master' into HEAD

* (FR #1097) Fix recurring text in Thank-you
* fix html include path. drop txt templates.
* Bugfix for damaged queue failmails
* update civicrm submodule for SA

Change-Id: I63ae6df89b2a11ca39e081cd305816eb85f4b6eb